Choke attachment for guns



Aug. 21, 1956 T. s. MOORE 2,759,286

CHOKE ATTACHMENT FOR GUNS Filed June 22, 1953 2 Sheets-Sheet l Thomas 5'. care IN V EN TOR.

Aug. 21, 1956 T. s. MOORE CHOKE ATTACHMENT FOR GUNS 2 Sheets-Sheet 2 Filed June 22, 195.3

Thomas 5. 00m

INVENTOR.

IGIP6 g/y. Fig. /5

C OKE ATTACHMENT FOR Thomas'S. Moore, Ly n aven, Va.

Appl cation Jun 22 125;, 'SeriaLNo. 363,073 is filaims. {CLAL- IQ) h inve t o rel tes Prima ily to a tac m nt f r guns v n pe t ins more Pa icularly to a chok atta ment for shotguns.

A p ima y o ject of hi nven on i to p o id an i p d fo m of choke attach. ent .for sho guns which i l effec uc essiv c ok ng act on to uccessive fi in of th gu th at achmen be ng so cons ucted n n e as t p mitany number of su cessive ch kin a t o s- An her obje t o thi n entio i to pro id animp ed form of choking at achmen ito shetg ns in con- .f rr i v With the regoing object wh ch includ m a fo select y ockin the a tachment in any one of it Po itions.

St ll a ot er object of t is invention s to provid a choke attachm nt for shet nn of trnggedendsturdv eonstruction which will lend itself readily to economical m P oduct on- An e o ject of th s inve tion to prov d an P ved form of .choh attachment tor shotguns which inc rp ate the eti et of ennreeoil in .eonjnnetion with he r tational e eet o resilient mean to n riort its s cessiv choking act onh s og th r w h other ehieets an ad a ta whi h w eenrn nb egnently appare t resid in th v tail o construction end operation a more 115 ereinafte de ed and claimed, ref ren e ing had to the .ae ernpanving drawing .iorrning a par ereo whe ein like num ralsrefer elilte p rts thro gh u and in WhiCh;

i ure 1 is a Pe spe t ve viewn ne term of t e chok attac ment ured in operative positio n the n o a gun barrel;

i r 2 is a longitudina section ta en hro gh h ss mb y h wn in Figur 1;

Fi ure 3 isan th r lengitn n l sect on similar to Fi ure t sh wing he position of the p rt in ful y choked Po t on;

Figure 4 i ransve s e tical s ct on taken s bstania y o g th plane of seet enline o F gu 2 howin a s f th inte na con tru tion;

F gure ,5 i a ot r tr nsverse verti al se t on t ke ubst nt a y a e ts the plane ref secti n line 5-...5 o F ure 2 shew ngde ai s o t e spring adjusting mechanism; t

F g re .6 is a ong tud nal sect on -t hen thr ugh a modifi d e m of attachmen Figu e 7 i a ert a ec ionta ensuhstant a v along the plane o se tion line t fi ure l how ng details o th l cking m chanism;

igu 8 i a pl n ie v e o e shee th a tachmen s own i Fi u e hes insan nes t nnnt the attachment conforming to full here firing-otthe gnn;

igur 9 i a v ew similar to figure .8 but showing an nterm diate positi n ht then taehrn nt con orming to a mo ified chok aetien;

Fi e =19 i ano herview imilerztosl i nses fi and? bet showing the fully choked position;

United States Patent 0 2,759,286 Patented Aug. 21, 1,956

Figure 11 is a view similar to Figure 8 but showing the relationship of parts for locking the attachment in convent n l r full bo firi g position;

Figu e i l-is a i w simil el i n ea but showing th at achment locked in the in ermediate ch i P s F g re 13 is a sectional en view. of a still fur her mo ified form of attachment;

Figure 14 is ,a side elevational view of the assembly shown in Figure 13 showing the attachment locked in the vinterme.diate choking position; and

,Figure 15 is a view similar to'Figure 14 showing the relationship of parts for efiecting ,a change in the locking action.

Referring now more particularly to Figures 1-5, reference numeral 10 indicates generally the barrel of a shotgun to which the attachment which is indicated generally by the reference character ,12 is secured. An inner sleeve 14 is provided at one end with the internally threaded portion 16 for engagement with a threaded end portion of the gunmuzzle for positive s'ecurement thereto and itqwill be seen that the other end of this inner sleeve is provided with circumferentially spaced, longitudinally extending slots 18 subdividing this end of the sleeve into ,a plurality of finger members 20. An outer sleeve 22 is disposed concentrically of the inner sleeve and one end thereof isprovided with a stepped aperture indicated generally y the reference character 24 which includes first, vsecond and'third steps '26, 28 and 30 resh et velv, the p rp se f w ieh ill h p s nt y pparent. A latch pin 32 is :t-hreadeclly received in a radial thr ad d bo e in the inner sleev '14 and he enlarged head 34 of this pin is disposed within the aperture 24 in the outer sleeve in the manner shown, the pin being p ovided h a ra ial th ea here thr ugh hich the th eaded shank 3.6 of a gh membe extends, th inn r end o t i sight m m Pre e a ly pr j c g in a threaded recess in the gunrnuzzle for securing the inner sleeve t ereto aga ns acc dental d sp acemen The inner sleeve 14 is provided with a circumferential shoulder 40 whi h ga es he nne urfac o the outer s eev a hok s eev ij is concen rical y ce e on the slotted end portion o the inner s e ve nd is a p vided with ,a circumferential houlder 44 in engagement with the inner surface of the outer sleeve. The choking sleeve is provided at its outer or free end with a gradually diminishing bore 46 which is adapted upon relative longitudinal movement between the inner and outer sleeve t e f t a con t c ing action upon the slotted f e nd of th in r sl e An inwardly directed shoulder or collar 43 is provided o th o ter sl e elh inen ege en with th pr y menti ned sh u d r 44 and an extern lly threaded retaining hinihle :51 i e ged w h the intern y threaded free end of the outer sleeve in the manner shown to engag again t the pposit side f the shoul r 44 to secure he outer sleeve and the choking sleeve together as a unit, An enlarged collar portion 52 of this thirnble may be knurled as shown for ease of manipulation. A eeil spring 541s disposed concentrically between the inner and outer sleeves and also extends partially between the outer and choking sleeve in the manner shown and the opposite ends of this coil spring are laterally bent as indicated by the reference characters .55 and 58 respectively for reception in apertures provided through the shoulders 48 and 4.0 respectively. In this respect, it will be noted that the shoulder is provided with one such aperture for receiving the end 56 as shown in Figure 4 and that shoulder so is provided with a plurality of such apertures, one of which receives the end 5?, as shown in Figure 5. his to be noted that the thimble 50 only slightly engages againstthe shoulder (44 on the choking sleeve and that the bore of this thimble is slidabl y and rotatably disposed with respect to the choking sleeve, as is the shoulder 48, so that the choking sleeve is free for rotation with respect to the outer sleeve and the thimble allowing muzzle gases to escape from the attachment.

In operation, the assembly is disposed in the initial position as shown in Figure 1 with the coil spring '54 urging I the inner and outer sleeve members in opposite rotational directions so as toengage the enlarged end 34 of the latching pin into engagement with the first stepped portion of the aperture 24 in the manner shown. 7 Since the bore of the inner sleeve member is substantially the same as the bore of the shotgun with which it is associated, the shot pattern obtained when the gun is fired in thisposition of the attachment will be conventional. When the gun is fired there is a reaction or kicking action which tends to throw the gun backwardly as the charge is projected forwardly. This is met and overcome by the shoulder of the user. Immediately, following the kicking of the gun the users shoulder rebounds causing the outer sleeve 22 as well as the choking sleeve 42 to shift inwardly or rearwardly relative to the gun barrel and the slotted end portion of the inner sleeve. This shifting is limited by engagement of the latching pin head 34 with the portion 64' defining the aperture 24 where upon the action of the coil spring 54 will effect a rotational movement of the outer sleeve 22 so that theenlarged'head 34 will be in engagement with the second stepped portion 28 of the aperture, the compression of spring 54 serving also to engage enlarged head 34 in stepped portion 28. The choking sleeve will, of course, be in such a position that its tapered bore portion 46 will have partially constricted the slotted free end of the inner sleeve so that the next shot fired from the gun will be partially choked, the operation of the attachment being repeated to engage the latching pin head 34 in the stepped portion 30 of the aperture 24, as will be manifest,

wherein the relative position of the parts of the attach- I ment'will be as indicated in Figure 3 wherein the full choke position of the attachment is obtained.

Referring now more particularly to Figure 6, a modified form of construction is shown which includes the inner sleeve member 66, the choking sleeve member 68, the coil spring 70, the retaining thimble 72 and the outer sleeve assembly which includes the forward sleeve portion 74 and the rear or barrel portion 76. The rearward end of the outer sleeve portion 74 is externally threaded as indicated by the reference character 78 and the barrel '76 is internally threaded to be engaged thereon. The inner sleeve may be provided with a pair of latching pins 80 integral therewith and one of which is provided with the internal threaded bore 81 for reception of a sight member.

Referring now more particularly to Figures 8-10, it will be seen in the operation of the choking attachment is similar to that previously described in conjunction with Figure 1 inasmuch as the pins 80 engage in apertures indicated generally by the reference character 82 and which includes the first stepped portion 84, the second stepped portion 86 and the third stepped portion 88. However, it will be seen that the stepped portion 88 is provided in the forward portion 74 of the outer sleeve while the other two stepped portions are provided in the barrel portion 7 6 thereof, the purpose of this construction being presently apparent. When the gun is initially fired with the attachment in the position shown in Figure 1, the pin 80 will be engaged against the surface 90 by movement of the outer sleeve assembly to the rear wherein the coil spring will move the outer sleeve assembly to the position shown in Figure 9 wherein the pin is in engagement with the stepped portion 86. Further firing of the gun will effect movement of the attachment to the position shown in Figure 10 wherein the pin 80 engages against the stepped portion 88 as will be obvious.

Referring now more particularly to Figure 7, it will be seen that the barrel 76 is providedwith the spring clip 92, one end of which is secured to the barrel as by the rivets 94 and it will be further seen that the opposite end of the spring clip is provided with the radially inwardly projecting ear 96which extends through a suitable aperture in the barrel 76 to project therebeyond into one of the circumferentially spaced apertures 98, 100 and 102.

' The purpose of this spring clip assembly is to maintain the various stepped portions of the aperture 82 in proper relation and in the position shown in Figure 7, the various portions of the stepped aperture arein the position as shown in Figures 8-10. However, should it be desired to lock the attachment in thefull bore or conventional shot pattern position as shown in Figure ll, it is merely necessary to pick up on the spring clip assembly to disengage the ear 96 from the associated aperture in the forward sleeve portion 74, whereupon the barrel 76 is rotated to the position .shown wherein the first stepped portion of the aperture is moved with relation to the pin 80 such that its surface 104 will prevent longitudinal movement between the inner and outer sleeve assemblies to maintain the attachment inthe full bore or conventional position. In this respectfitwillbe noted that sired to lock the attachment in the intermediate choke position as shown in Figure 12, it is merelyv necessary to rotate the barrel 76 so that the aperture 98 therein is engaged. by the ear.96 of the spring clip assembly wherein the relative position of parts willbe'as shown. Naturally, the threaded portion 78 of the forward sleeve portion 74 is cut away from its rear end forwardly therefrom to allow proper movement of the pin '80 with respect thereto, as will be manifest.

Referring now more particularly to Figures 13-15 wherein a modified form of locking assembly is shown, it will be seen that the stepped aperture 106 and pin 108 are as previously described as'is the forward portion 110 of the outer sleeve and'the inner sleeve 112. However, a retaining thimble 114 is provided in threaded engagement with the internal threaded portion of the outer sleeve member 110 and an'edge of the outer sleeve portion 110 adjacent the barrel 116 is provided with the pin member 118 in the manner shown whereas the corresponding edge in the barrel is provided with the grooves 120 in the manner shown. When it is desired to lock the attachment in the various positions corresponding to Figures 8, 11 and 12, the retainer thimble 114 is backed off as shown in Figure 15 and the barrel 116 slid rearwardly to disengage the pin 118 from its associated groove 120 and the barrel thereafter properly positioned with the desired groove 120 in engagement with the pin whereupon the thimble is rethre'aded tightly against the assembly to efiect the desired locking position of parts.

From the foregoing, it will be readily apparent that any practical number of sequential choking operations may be obtained by providing the corresponding number of stepped portions in the stepped apertures. However, since most state laws require that no more than three shells be loaded in the shotgun during hunting of most game animals, the device as herein shown and described pertains to three successive choking actions. It will also be manifest that the particular taper of the choking sleeve members may be varied to provide any desired degree of sequential choking action of the shot pattern as the gun is successively fired. As previously noted, one end of the coil spring is selectively engageable in various apertures in the shoulder of the outer sleeve member so that its tension can be varied when desired to effect the proper operation of the attachment.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur greases to those skilled in the art, it isnot desired to limit the invention to the exact construction shownand described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of. the appended claims. I

What is claimed as new is as follows:

1. An automatic shotgun choke comprising an inner I sleeve adapted to be attached to the end of a shotgun barrel, said inner sleeve having-a constrictable free end portion, an outer sleeve slidable on said inner sleeve, said outer sleeve including means responsive to movement of the outer sleeve along the inner sleeve, forsuccessively constricting the free end of the inner sleeve, coil. spring means urging the outer sleeve reciprocably androtationally with respect to the inner sleeve, a pin secured to and projecting radially from the inner sleeve, said outer sleeve having a longitudinally stepped aperture through which said pin projects, and adjusting means engageable between said spring and one of said sleeves for adjusting the residual tension on said spring.

2. An automatic shotgun choke comprising an inner sleeve adapted to be attached I othe end of a shotgun barrel, said inner sleeve having a constrictablefree end portion, an outer sleeve slidable on said inner sleeve, said outer sleeve including means. responsive to movement of the outer sleeve along the inner sleeve, for successively constricting the free end of the inner. sleeve, coil spring means urging the outer sleeve reciprocably and rotationally with respect to the inner sleeve, a pin secured to and projecting radially from the inner sleeve, said outer sleeve having a longitudinally stepped aperture through which said pin projects, a collar rotatable in said outer sleeve, said collar having a longitudinally stepped notch through which said pin projects in some of the longitudinal positions of the outer sleeve on the inner sleeve, said collar being adapted for limited rotational movement on said outer sleeve to prevent longitudinal movement of the outer sleeve on the inner sleeve, and adjusting means engageable between said spring and one of said sleeves for adjusting the residual tension on said spring.

3. In a removable recoil responsive choke attachment for guns comprising a first sleeve including one end removably attachable to a gun muzzle, the other end of said sleeve including a constrictable end portion, a second sleeve circumposed on said first sleeve, said second sleeve comprising a free end portion projecting beyond the constrictable end portion of said first sleeve and including an internal annular camming tapered bore portion reciprocably and rotatably engageable on said constrictable end portion and operable to constrict the first sleeve in response to relative reciprocable movement of said second sleeve due to firing recoil of said gun, means engageable between said first and second sleeves for retaining the same in a fixed relative first position for firing of a first round of a gun, automatic latching means and sequentially-operated reciprocating and rotating spring means engageable between said sleeves for automatically reciprocating and then rotating the second sleeve to several other predetermined choke positions in response to firing of successive rounds, and means engageable between said spring means in one of said sleeves for applying a predetermined tension on said spring means urging rotation between said sleeves.

4. A choke attachment for guns comprising an inner constrictable sleeve and an outer constricting sleeve slidable thereon, said outer sleeve having longitudinal movement on said inner sleeve in response to recoil of a gun upon which the attachment is mounted, means on the outer of said sleeves engageable with the inner of the sleeves upon relative longitudinal movement therebetween constricting a portion of the bore of the inner sleeve, means engageable between said sleeves automatically latching said outer sleeve assembly in predetermined longitudinal positions on the inner sleeve assembly to effect a plurality of constricted choke defining conditions successfully-obtainable due to recoil of the associated gun, means for selectively locking the outer and'inner sleeves in a single fixed position, said last mentioned means comprisinga resilient member engageablebetween said sleeves for urging relative rotational movement therebetween, and a stop pin extending laterally from one of said sleeves through the other sleeve, said other sleeve including a circumferentially spaced pluralstepped aperture portion receiving said pin, the'steps in said aperture portion corresponding to various positions of constriction defined by the outer sleeve relative tothe inner sleeve, and adjusting means engageable between said resilient member and one of said sleeves for providing a residual tension on said resilient member.

5. A' choke attachment'for guns comprising a. first sleeve adapted for attachment at one end of the gun muzzle, said sleeve having its other end provided with a'series of circumferentially spaced slots, a second sleeve disposed concentrically of said first sleeve, said second sleeve hav- "ing a free end projecting beyond the slotted end' of the first sleeve and havingthat portion of its bore between said slotted end of the first sleeve and its free end tapered, said second sleeve being arranged for sliding movement on said first sleeve to a plurality of positions in response to recoil of the gun for eifecting at least three progressive constrictions of said slotted end of the first sleeve, and means for automatically latching said second sleeve successively in its various positions, said first sleeve including a radial shoulder engaging the inner surface of said second sleeve, a projecting radial shoulder on said second sleeve, said means including a coil spring having opposite end portions received in said respective shoulders to urge said second sleeve rotationally with respect to said first sleeve, a lateral pin element on said first sleeve projecting through a circumferentially stepped plural-aperture portion in said second sleeve, the engagement between said pin and the stepped portions of the aperture portion efiecting automatic latching between said sleeves, and coil spring adjusting means operatively engaged between one end portion of said coil spring and one of said sleeves for imposing an initial tension on said coil spring.

6. A choke attachment for guns comprising a first sleeve adapted for attachment at one end to a gun muzzle, said sleeve having at its other end provided with a series of circumferentially spaced slots, a second sleeve disposed concentrically of said first sleeve, said second sleeve having a free end projecting beyond the slotted end of the first sleeve and having that portion of its bore between said slotted end of the first sleeve and its free end tapered, said second sleeve being arranged for sliding movement on said first sleeve to a plurality of positions in response to recoil of the gun for effecting at least three progressive constrictions of said slotted end of the first sleeve, and means for automatically latching said second sleeve successively in its various positions, said first sleeve being provided with a radial shoulder engaging the inner surface of said second sleeve, a projecting radial shoulder on said second sleeve, said means including a coil spring having opposite end portions received in said respective shoulders to urge said second sleeve rotationally with respect to the first sleeve, a pin on said first sleeve projecting through a circumferentially stepped aperture in said second sleeve, the engagement between said pin and the stepped portions of the aperture effecting the automatic latching between sleeves, one of said shoulders having circumferentially spaced apertures selectively receiving the corresponding end of said coil spring for varying the tension between said sleeves.

7. A choke attachment for guns comprising an inner constrictable sleeve assembly and an outer constricting sleeve assembly slidable thereon, said outer sleeve assembly being longitudinally movable in response to recoil of an associated gun, means on the outer sleeve assembly engageable with the inner sleeve assembly upon relative longitudinal movement therebetween to constrict a portion of the bore of the latter, and means for automatically latching said outer sleeve assembly in various longitudinal positions on the inner sleeve assembly to effect at least three progressively greater constrictions of the latter in response to successive recoil of the associated gun, said inner sleeve assembly being provided with a radial shoulder engaging said outer sleeve assembly and said outer sleeve assembly is provided with a projecting radial shoulder opposing the first-mentioned radial shoulder, said last means including a coil spring having opposite end portions received in said respective shoulders to urge said second sleeve rotationally with respect to the first sleeve, a pin on said inner sleeve assembly through a circumferentially stepped aperture in said outer sleeve assembly, the engagement between said pin and the stepped portions of the aperture efiecting the automatic latching between the sleeve assemblies, one of said shoulders having circumferentially spaced recesses selectively receiving the corresponding end of said coil spring for varying the tension between said sleeve assemblies.

8. In a removable recoil responsive choke attachment for guns comprising a first sleeve including one end removably attached to a gun muzzle, the other end of said sleeve including a constrictable end portion, a second sleeve circumposed on said first sleeve, said second sleeve comprising a free end portion projecting beyond the con strictable end portion of said first sleeve and including an internal annular camming tapered bore portion reciprocably and rotatably engageable in said constrictable end portion and operable to oonstrict the first sleeve in response to relative reciprocable movement of said second sleeve due to firing recoil of said gun, means engageable between said first and second sleeves for retaining the same in a fixed relative-lfirstposition for firing of a first round of a gun, automatic latching means and sequentially operated reciprocating and rotating spring means engageable between said sleeves for automatically reciprocating and then rotating the second sleeve to several other predetermined choke positions in response to firing of successive rounds, said automatic latching means including a third sleeve circnmposedon said first and second sleeves and reciprocable relative thereto, said third sleeve being rotatable with said second sleeve, and latch pin means extending laterally from the first sleeve to a circumferentially plural-stepped portion in said third sleeve for defining a plurality of choke positions between the relatively movable sleeves, said sequentially operated reciprocating and rotating spring means including a coil spring circumposed over said first and second sleeves with opposite end portions in fixed and abutting engagement with said sleeves, and adjusting means engageable between one end portion of said spring and one of said sleeves for pro viding a residual twist to said spring.

References Cited in the file of this patent UNITED STATES PATENTS 

